The long-term lightcurves of SySt are usually reconstructed from
multi-band photometric campaigns (e.g. [1]}, [2]}, [3]}), from digging historical plate
archives (e.g. [4]}), or searching the public
databases of all-sky patrol surveys (e.g. [5]}, [6]}, [7]}). Aside from the obvious effect
of eclipses for systems seen at high inclination, the orbital motion may
affect also the lightcurve of SySt seen at intermediate inclinations. The
basic type of orbital-induced modulation of the lightcurve of non-eclipsing
SySt is shown in Fig. REF  (adapted from
[8]}), aiming to highlight the interplay between
the irradiation effect (better visible in the bluest photometric bands and
for burn-SySt) and the ellipsoidal distortion (which is more prominent
in the reddest bands and in acc-SySt).
